Green MP Julie Anne Genter last week made public an email she received from an anti-fluoride activist, suggesting Genter's two miscarriages - which she spoke about publicly in March - were due to her fluoride intake.

"I read in the paper a little while ago that you had had two miscarriages," the letter, which Genter posted on her Facebook page with the senders name blacked out, said. "Therefore I thought I would send you this information on fluoride." It contained a link to a blog site, purporting to link fluoride to stillbirths.

Genter, who as an MP is used to receiving offensive emails but is also a woman and a human, felt that this crossed a line. "I was so taken aback by it," she told me. "I was really shocked that the email linked my personal experience of miscarriage with water fluoridation, and I didn't feel that I should keep quiet about that."

At this point, we were potentially dealing with a rogue email. In the meantime, Auckland University scientist Michelle Dickinson rigorously debunked the sender's claims on her Nanogirl blog. (To sum up: studies show fluoride is safe, and prevents tooth decay. There are no links to miscarriage or stillbirth.)

That's when the anti-fluoride fearmongers stepped in, goading Dickinson on Genter's Facebook post and via email to agree to a public debate. When she said she would consider it, they manufactured a press release promoting the non-existent debate to garner publicity.

Around one in five pregnancies end in miscarriage, defined as before 20 weeks gestation. That's a lot of New Zealand women, and their partners, who have been through an extremely painful time that even close friends may not know about. This could be because, while miscarriage is random, mostly occurs for unknown reasons and is not a woman's fault, many women still feel guilty and blame themselves.

The pretending-not-to-be-pregnant until 12 weeks; the feeling after the event we shouldn't share our loss; these create a cone of silence around miscarriage. Into this silence, myths like the fact women could have done anything to prevent it flourish.

Genter told the NZ Woman's Weekly about her miscarriages for these reasons, to help others. To have her pain thrown back at her and then leveraged off is vile. Talking about miscarriage is already hard enough.